NEW YORK -- Matt Sassi is not crazy, nor is he someone who has ever longed for his 15 minutes of fame. He is, however, the kind of guy who believes that when you make a pact with a friend over burritos, it's important to keep it.

If Bartolo Colon ever hits a home run, Sassi declared during the World Series, I'm getting a commemorative tattoo.

No one at the table imagined that Sassi would ever have to deliver on his declaration. But you can guess what happened after Colon went deep for his first career home run on May 7 against the Padres. Sassi, a Middletown, New York, native who lives in San Diego, became the proud owner of a giant, grinning, goofy likeness of Colon on his right shoulder. It's a tattoo that is -- like Colon -- somehow both joyful and outlandish.

It also might be the best way to explain the Bartolo Colon phenomenon.

"I've always been fascinated by him," Sassi said. "I feel like he embodies the way the sport should be. He does things that you don't expect him to do, which is what makes him so great."

On the surface, it's surprising that baseball fans have chosen Colon as the one to adore. He's a 43-year-old pitcher with a Santa Claus physique and a complicated past: steroids, a nontraditional elbow surgery, a second family. But that's exactly what has happened with Colon the past two seasons. In the twilight of his career, at an age when most great baseball players are limping home, both physically and spiritually, Colon has become something of a national treasure, our round mound of mirth.

His jolly stretching exercises, his graceful pirouettes, his wild swings that send his helmet flying, they've all become part of his legend. Colon is the human GIF that keeps on giving.

Colon admirers wait for the strikeouts that lead to flying helmets. Mitchell Leff/Getty Images

YOU CAN MEASURE the love for Colon in both anecdotes and facts, but let's start with the obvious: He is still surprisingly good at baseball.

Despite being the oldest player in either league and despite throwing essentially one pitch (a fastball, which he relies on 87.8 percent of the time), Colon is ranked in the top 20 in the National League in ERA (2.87), WHIP (1.17) and WAR (2.8). He is the active all-time leader in wins, with 225, a feat that is even more remarkable when you remember that he looked like he was toast in his 30s. He won the Cy Young Award in 2005, but from 2006 to 2009, Colon pitched only 257 combined innings. Then he missed the entire 2010 season because of elbow and rotator cuff injuries, and received a procedure in the Dominican Republic that involved injecting bone marrow and stem cells into his elbow and shoulder.

Once a flamethrower, he has since reinvented himself as an artist with pinpoint control. Among pitchers with at least 80 innings pitched, only Clayton Kershaw has walked fewer batters than Colon.

But stats hardly scratch the surface of Colon's appeal. They don't explain why fans print giant pictures of his face and wave them at ballparks around the county. They can't pin down why social media went bonkers after his home run or why players around the league were giggling and texting like teenagers that afternoon.

Colon has become a reminder that sports don't need to be deathly serious all the time. Watch him grab his belly and laugh in the dugout, watch him flip a ball behind his back to make an out, watch him carry his bat to first -- there's an everyman appeal. After Colon's home run, Topps put out a $9.99 commemorative trading card to celebrate the feat. So many orders poured in (nearly 9,000 in 24 hours) that the card smashed the company's previous sales record of 1,808 for Jake Arrieta's no-hitter.

Colon's first career home run came on May 7 in San Diego, just weeks before the pitcher's 43rd birthday. Denis Poroy/Getty Images

Even James Shields, the man who surrendered the home run, enjoyed the moment.

"I am a big Bartolo Colon fan. I am a fan of what he is all about," Shields told reporters the day after Colon's blast. "Obviously, I didn't want it to happen to me. I'm happy for him."

So the better question might be: Why do we look at Colon's faults and vices -- the same things we use to condemn and criticize other athletes -- and shrug our collective shoulders?

On May 18, just a week after Colon belted his historic home run, the New York Post published a quintessential tabloid scoop: Colon, who has four children and has been married for 21 years, was being hauled into family court in Manhattan for his failure to pay child support to a Washington Heights woman who was revealed to be the mother of two additional children. The Post described the messy affair as the unmasking of Colon's "Secret Family."

The day the story broke, Colon was scheduled to pitch at home against the Nationals, which meant he would be unable to avoid commenting on the story. The confluence of events had all the makings of a New York media tabloid bonanza, especially when Colon turned in his worst start of the year as he walked five batters and sweated his way through just 4 2/3 innings. As a small pack of reporters waited for Colon postgame, an uncomfortable silence hung over the Mets locker room.

But Colon, who conducts all his postgame interviews in Spanish with the help of a translator, seemed unfazed. He stood in front of his locker, a gray T-shirt over his large belly, looking relaxed. Eventually, after a few polite baseball questions, a reporter broached the subject of Colon's "secret family."

Was it difficult to focus tonight with all of that controversy swirling?

"No, I have nothing to add. I don't really care to talk about personal stuff," Colon said, and then he smiled. No one asked another question.

Despite controversies, Colon has become a fan favorite over his past two-and-a-half seasons with the Mets. AP Photo/Frank Franklin II

Within a week, the controversy -- if it even rose to such a level -- had all but died. It was almost reminiscent of 2012, when Major League Baseball suspended Colon for 50 games after he tested positive for testosterone while a member of the Oakland Athletics. He served his suspension, re-signed with the A's, pitched well and made the American League All-Star team the following year. Today, the suspension rarely comes up, unless you mention it to someone in baseball who enjoys speaking his mind.

"Why is he still pitching so well? Steroids, obviously," Orioles manager Buck Showalter said, then held a poker face for a full five seconds before breaking into a mischievous smile. It was a joke, he said.

"It's kind of hypocritical, isn't it? What does that say about society?" Showalter continued, commenting on why controversy sticks to Colon like Teflon. "Some people would say it's forgiving. Others would say as long as you pitch well, it doesn't matter."

Is it because Colon is goofy and fun and smiles a lot? That's probably part of it, Mets outfielder Curtis Granderson said.

"I think people can't help but be drawn to Bart's mannerisms," Granderson said. "He's never too high, he's never too low, he's just out there enjoying himself. When you're young, everything about the game is fun. The only thing that changes is you're playing in front of more people, the stands get bigger, there's more people watching. The game should still be the same. We forget that. We tend to be at our best when we're having fun, and he's such a great example of that."

It's not just Granderson. Matt Harvey said he wishes he could play the rest of his career with Colon. Noah Syndergaard called Colon his personal Yoda, his idol and his mentor. Michael Conforto raved about Colon's intelligence and attitude. If you polled the clubhouse, Colon would likely be the team's most popular player. The reasons behind that honor would be simple: He handles the business of pitching like a professional and has no interest in the rest of baseball's pomp and seriousness.

"He's not your typical starting pitcher," Mets third baseman David Wright said. "I'd kind of compare it to the NFL wide receiver, where they're kind of the divas of the team. They come in, they put their headphones on immediately, they have to eat a certain meal, they get to pick what uniforms we have to wear, what music we listen to. Everything is catered to them for the day. With Bart, it's the opposite. He's walking around slapping guys in the back of the head, making jokes, he's laughing. I really enjoy that. He genuinely enjoys what he does."

Every time you think you have Colon figured out, he finds a new way to surprise. In late May, Colon faced the Nationals again, this time on the road. At some point during the game, he decided his back was stiff, so when he came to the plate and Washington pitcher Gio Gonzalez threw a knee-buckling changeup, Colon leaned back and told catcher Wilson Ramos to have Gonzalez throw fastballs over the plate. He promised not to swing. True to his word, he didn't.

"I thought it wasn't worth it to swing," Colon told reporters after the game. "I swing at the balls pretty hard, and I thought, not worth making my back worse, so I told their catcher from the beginning, 'Just throw it right down the middle. I'm not swinging.'"

At times, Colon resembles a Will Ferrell sketch, but ... real. He's so flexible, he can do the full splits, like a ballerina. Michael Conforto said sometimes he watches Colon run down line drives in the outfield, and he looks -- in short bursts -- like a thick Willie Mays. "He'll make crazy catches, and he'll go up against the wall," Conforto said. "The fans who are there for batting practice, they love seeing him make those crazy catches." But mostly, Colon just makes teammates laugh.

"Bart had one of the best quotes I've ever seen," Wright said. "Someone asked him if that was his first home run. He said, 'No, I hit a lot of them in Friday night softball games back home in the Dominican.' That's just him in a nutshell. He loves the game, and he plays softball at home in the offseason, apparently."

Colon won the American League Cy Young award in 2005, when he was with the Angels, and celebrated with friends back in the Dominican Republic. AP Photo

THERE HAVE BEEN times in Matt Sassi's life when he felt a little anxious, lost, even depressed. Raised in Middletown, he went to school there, but not long ago, a job as an accounts payable clerk opened at a community college in San Diego. It required a cross-country move. Soon, Sassi found himself in a big city far from home. What kept him upbeat, of all things, was his lifelong obsession with the Mets.

"The Mets have always been kind of looked down upon, even with two World Series wins," Sassi said. "I see myself as a Met, per se. I was never very good at baseball. But I always loved how upbeat and happy Mets fans were after wins. It was a team that made sense to me. I never wanted to be the kind of person who was really upset if my team loses, like I expected them to win all the time. They've just always been something I could be happy about."

Loving the Mets can feel like drinking a potent cocktail of comedy, skepticism, hope and longing. But rooting for any baseball team -- an act of communion in which we gather together daily with friends and strangers to believe -- can also be a unifying force.

Whenever Colon pitched, Sassi's friend Anthony Triola would text him, usually when Colon came to bat, and the two Mets fans living far away from home would pray that this might be the big moment. Until this season, Colon had never hit a home run, but it was his custom to swing from his heels at nearly every pitch. Sassi and Triola would chuckle as they watched Colon helplessly flail at pitches, with his belly jiggling in one direction and his helmet flying in the other. It made for great entertainment, if not great offense.

When the Mets traveled to San Diego for a four-game road trip the first week of May, Sassi badly wanted to attend one of the games, especially because the Mets' fan club, the 7 Line Army, was organizing an outing for the series. Initially, Sassi thought he wouldn't have enough money for a ticket, but a fellow Mets fan sold him one for a reasonable price, and suddenly, he was at Petco -- with Triola -- surrounded by a pseudo-family of Mets fans.

No regrets for Matt Sassi, who now has a tattoo commemorating Colon's home run. Matt Sassi

"I told a bunch of people in our section about the pact: that if he hit a home run, I was getting a tattoo," Sassi said. "But I didn't really think too much about it."

In the second inning, facing Colon, Shields tried to sneak a 91 mph fastball over the middle of the plate on a 1-1 count. In that moment, Colon looked more like Babe Ruth than a pitcher with a .094 career batting average. He hammered the ball high in the air and over the left-field fence, and as Mets fans went bonkers, Colon began one of the slowest, most satisfying home run trots in baseball history. On social media, it was pandemonium. Inside the stadium, it was pandemonium.

"As soon as he swung, my brain exploded," Sassi said. "It was insane. It's very hard to describe in words. Actually, I think my brain melted. I was so stoked. Everyone around me just kept screaming, 'You've got to get that tattoo!'"

It took the tattoo artist almost four hours to complete his work. It didn't hurt, Sassi said. He felt nothing except joy. When the scars began to heal, he sent a picture of his shoulder to the 7 Line Army blog, and as soon as it was posted, it went viral.

"Some people said it didn't look like Bartolo at all, that it looked like a California Raisin or that he looked like Chris Christie," Sassi said. "Well, I didn't want it to look like an exactly portrait of his face. I wanted it to look a little cartoony. I wanted it to look different. I wanted his helmet to be falling off and him to have a goofy look on his face because that's exactly how it always played out in my head."

Sports have a habit of making us cynical, Sassi said. While that's understandable, it doesn't mean you need to give in to it. Years from now, when he looks at his tattoo, Sassi is convinced he won't regret it. All he's going to remember is that moment at Petco Park, when the sun was shining, when he was sitting with one of his best friends and when they witnessed one of the most unlikely moments in baseball history. It's easy to understand why you'd want to make a day such as that feel permanent.

"This wasn't something I felt like I had to do," Sassi said. "It's something I really wanted. I wanted to remember that moment."

Colon didn't need ink to remember what happened. He called it, without hesitation, the biggest moment of his long career. He took his time, lumbering around the bases with a huge grin on his face. When he finally returned to the dugout, he kept touching his heart. He told his teammates he couldn't believe how quickly it was beating.